Mercury-vapor lamp.



L. E DEMPSTER. MERCURY VAPOR LAMP. APPLICATION IILED MAR. 27., 1905.

974,037. Patented 001;. 25, 1910.

4 Inventor Leon ard E. Dempster LEVONARD r5. 'nmirs'rnn, or scHE'uEc'm-mr, NEW YonK,-;-Ass1e1ro11.,ro Gums: ELECTRIC COMPANY, 'A CORPORATION or sNEW= YORK.

MERCURY-Tarantella 1' to provide such tubes with a high resistance filament which, at starting, connects the two electrodes of the tube, but which may be separated from the mercury electrode, there by forming an incipient are at the surface of the mercury, which are extends immediately to the cooperating electrode.

'It is the object of this invention to pro-' vide an improved lneans for producing this incipient are at the surface of the mercury electrode.

My improvement also embodies certain other novel features which will be ointed out more in detail in the following descriptiontaken in connection with the drawing which forms a part of this specification.

The figure shows an evacuated chamber or tube 1 provided with a carbon anode a mercury cathode 3, and a high resistance filament 4 of carbon or other suitable ma terial. A lower tubular extension 5 of the evacuated tube is surrounded by a solenoid 6 and is separated therefrom by a sleeve 7 of brass which serves as a mechanical support for the tube 1.. Floating in the merc'uryelectrode 3 is a glass plunger 8 comsealed and containing a bundle of soft iron wires 10 which (x institute an armature forthe'solenoid 6. The upper-apart ll of the glass plunger 8 is open at the top and constitutes a cup for JJ'ICICHI). Dipping in this cup ofanercury is the lower end of filauu-nt 4. A tubef'lQ of glass or other insulating material. is supported from the side wall of the chamber 1 and surrounds the lower end of filament =t toprotect it from the destructive action of arcing as hereinafter more fully set. forth. '1he anode 2 is connected to the positive, side of the current source through the 'inagneti zing coil of an automatic cut-out 13, the armature 14: of which Specification of Letters Patent.

Application filed March 27, 1905. SertatNo. 252,177.:

out 13 and filament 4., thereby allowing cm pr sing a lower eomparti'nenti'fi hermetically" The protecting Patented Oct. 25.- .1910. 1,,

serves to connect solenoid 6 to the positive 'i'f side of the current source. The other t'er minal oflsole'noid'ti is'connected to the nega-";- tive side of the current source througlr'a" resistance 15, though if desired the solenoid "(so may be so proportioned that the resistance 15 is unnecessary The mercury electrode is connected to the negative side of the cur rent source through a st'eadying 'r'esistance 16, I

At starting, the various parts of the a'j ratus are in theposition shown in thc'fign're, and current flows from the source through? solenoid 6, thereby drawing down the 'p'luna'" ger 8 until the mercury outside the plunger overflows "the upper edge of cup 11 and makes contact'wit-h the'mercury in' thecupi This eompletes the circuitfrom .the positive: pole of the cnrrent source through tlie'cu rent'to flow from the mercury in on" 11 to the main body of mercury constituting the cathode and thence back to the current source-through resistance 16. This flow of, current through cu t out'13 lifts the arma so ture 14 and "demagnetizes solen'o'id (3, therel'iy 3i allowing plunger 8 to rise by its own buo'y-" aney. This movement causes the upp'eredge' of cup 11 to cut. through the mercury layer and thus separate the mercury on the' outside of the cup from that on the inside, This movement does not, how'e\-'er, destroy the electrical connectionbet-ween tliestativo"; bodies of mercii for an ar'c' is established at this pointand current continues to fio'w" from one mercury surface to the other. This starting arc renders conductive the space within tlle tllljk." so that. the flow of current takes place from anode 2 to cathode 3, and the lamp then operates in the usual'manncr;

'l'he solenoid (i. it will 'be observed, is connet-ted in.shuut to the mains only momentaril whilethe lamp is being started. it. may therefore be made of relatively very sl'na'll wire. as it is not under the influence of cur- 0 rent long enough to become unduly heat-ed.

sleeve 12 of glass around the lower end of filament. 4, while it may be omitted, has the advantage that it. with oer- I tainty' confines the starting are entirely to the mercury surfaces, so that no action dc-j strueltive to the filament can occur no inatter how long this are may continue to exist before the lamp starts.

Tn lamps as heretofore constructed some diliiculty has been experienced in the carelcssness of \vorkn'len in connecting the lam s l in circuit with the terminals reversed. if l such a mistake is made in connecting L3) alamp of the type in which a moving lament establishes an incipient are at the surface of the mercury electrode, there is dan-' ger that this are will continue to play on the filament as cathode without startin the lamp, and will consequently burn 0 the lower end of the filament. This diliiculty is" entirely overcome by my improved construction in which the incipient are always occurs between mercurysurfaces no matter whether the lamp is properly connected up or not.

Vlhat I claim as new and desire to secure by Letters Patent of the United States, is,

1. In a vapor electric ap aratus, an evacuated chamber, a mercury e ectrode therein, a stationary high resistance filament in said chan'iber, a conducting body electrically connected to said filament butinsulated from said electrode, and means for automatically establishing electrical connection between said conducting body and said electrode.

2. In a vapor electric ap arat-us,'an evacuated chamber, a mercury c ectrode therein, a filament in said chamber, a body of mer cury elcctricallfy connected to said filament but separated rom said electrode by an insulator, and automatic means for moving said body of mercury into. electrical connection with said'mercury electrode.

3. In' a va )or electric apparatus, a mer cury elcclrotle, a plun er floating in said mercury electrode, a liody of conductin li uid carried by said plunger and insulator from said mercury electrode, a filament dip-. ping in said conducting liquid, and means for moving said plunger.

-l. The combination of an evacuated envelop, electrodes therein, means within said envclop for establishing a direct connection bc'l ween said electrixles through a solid conductor, and means for severing said connection bctwcrn surfaces of vaporizable matcrial.

5. In a vapor electric apparatus, a mercury electrode, a plunger of insulating material limiting in said mercury electrode, a body of conducting material carried b said plunger, and aut matic means for )r ucing a momentary conla'ctbetween sai mercury clecl rode and said body of conducting malerial.-

6. 'In a vapor electric apparatus having a mercury electrode, a second body of mercury movable with respect to said mercury electrode, a high resistance filament dipping in said Second bod of mercury, and automatic means for pr( ucing a monientar contact between said mercury electrode ant said second body of mercury.

7. Tn a vapor electric apparatus, a mercury electrode, a plunger suspended in said mercury electrode, a body of conducting material carried by said plun er and insulated from said mercury electro e, and automatic means for moving said plunger to roduce a momentary contact of said body 0 conducting material with said mercury electrode.

8. In a vapor electric apparatus, a mer-' cur v electrode, a plunger suspended in said mercury electrode, a body of conducting material carried by said plunger and insulated from said mercury electrode, a high resistance filament electrically connected to-said body of conducting material, and means for moving said plunger to establish an electrical connection between said filament and said mercury.electrode.

S). In a vapor electric apparatus, an evacuated chamber, an anode and a mercury cath ode therein. a source of current connected to said cathode, a second-body of mercury connected to the other side of said current' source, and means for lowering said second body of mercury into contact with said mercury electrode and subsequently raising the same to produce an incipient or startinganc in said evacuatwl chamber.

10. In a vapor electric apparatus, an evacuated .chamber. a mercury electrode therein, a high resistance filament .in said chamber, a non'conducting tube inclosing one end of said filament, means for electrically connecting said end of the filament with' the mercury electrode,' and means for breaking contact between a portion of the body of mercury engaging said filament and the main body of mercury.

11. In a vapor electric apparatus, an evacuated chamber, a mercury electrode therein. aplunger suspended in said mercur electrode and carr in a second bodv of mercury,.a filament dipping in the mercury carried by said plunger, and means for moving said plunger to produce an are between said electrode and the mercury carried by said plunger. 12. In a .vapor electric apparatus, an evacuated chamber, a high resistance filament therein, a plurality of mercury bodies therein, means for producing an arc between said mercury bodies by current carried by said filament, and means for protecting said filament from the destructive action of said are. a r 13. In a vapor electric apparatus, an evacuated receptacle, a mercury electrode therein.a conductor extending below the surface of the. mercury, and means interposing a movable barrier of insulating material between said conductor and a portion of said body of mercury.

14. In a vapor electric apparatus, an evacuated receptacle, a mercury electrode therein, a conductor extending below the surface of the 'lncrcur and magnetically 'vaporizable material.

controlled means for interposing a barrier establish an of insulating. material between said conductor andv a portion of said body of mercury.

15. The combination velop, electrodes therein, at least one/of 1 portions 05 said electrode and are thereb tween.

19. In a vapor electric apparatus, an fevacuated eceptacle, a vaporizable electrode therein, a cup of insulating material movable to withdraw a which is of vaponzable material, a solid porizable material, and means for moving conductor initially carrying current within said cup.

sai, envelop, means for connecting said -20. In a vapor electric apparatus, an solid conductor with said vaporizable elecevacuated envelop, a mercury electrode and a solid electrode therein, a mercury body permanently connected to said solid electrode by a conductor located within said envelop, and means for producing a relative movement between said mercury electrode d said mercury body to-initiate an arc to said-solid electrode.

n a vapor electric apparatus, an evacuated envelop, a body of vaporizablc material therein initially out of contact with said envelop, means for lowering said body, and means for starting an arc in said en velop .when said body rises' 22 n a vapor electric apparatus, evacuated envelop, a

tween surfaces of vaporizable material.

16. The combination of an evacuated en velop, electrodes .therein at least one of which is of vaporizable material,

producing an are between said electrodes by initiating, a starting arc in said path between surfaces of similarly vaporizable' material.

17. The combination of an evacuated envelop, electrodes therein at least one of which is of vaponizable material, means for passing current directly from one electrode to the other through a solid conductor located within the envelop, and means for forming an arc in said envelop in series with i said solid conductor between surfaces of rel .ing an are when said plunger is released.

In witness whe eof, I have hereunto set I my hand this 23r day of March, 1905.

l LEONARD E. DEMPSTER.

In a vapor electric apparatus. an.

evacuated leceptacle, a vaporizable electrode therein, means for passing current Witnesses: through said electrode and means for then BENJAMIN B. HULL,

movingan insulating barrier to separate. HELEN Oarono.

portion of said va.

fluid body therein, a 

